我有一个具有相同字段的column1
和column2
;我想从两张表中得到distinct
row count
。
我试过了:
SELECT COUNT(DISTINCT test_setting.imei)
FROM test_setting, wcdma_tests
WHERE wcdma_tests.imei = test_setting.imei;
试试这个:
SELECT COUNT(DISTINCT i.imei)
FROM test_setting i join wcdma_tests a on i.imei = a.imei